I was the same way about Sonos radio but tbh I’ve ignored it and don’t even see it anymore. If it really bothers you just return it and go with something that doesn’t do this, life’s too short man. A suggestion don’t do LG or Vizio. 

Discontinued? No idea what that means and you didn't include a link to the problem.

You can return your Sonos for a refund if you haven't kept them too long, if you have you can get a good price on ebay or the like and get something that doesn't have a link to a service you don't want.

Thread closed. 

What thread? What default setting?

Threads are closed automatically after they have not been added to for a certain period of time.

The forum software automatically closes threads when no new comments have been posted after a given period of time.

The ability to remove Sonos Radio has been requested before, however, it is not currently possible to do.

Although Sonos Radio is the default content service, you can change this by going to Account > Content Services > Your Preferred Service

That helps, still don't know which of many, many Sonos radio topics you are looking at so the guesses as to why by others will have to do.

You don’t need to know what thread. OP points this out as to why they have started a new topic instead of the hundreds of other threads talking about the issue as ​@Birman explains in their post (they want to remove the service). I don’t think the others even bothered to read it lol.